Transmission for a Rail Vehicle Drive Train

ABSTRACT

The invention concerns a transmission for the drive train of a rail vehicle having an input for connecting a drive motor of the rail vehicle;
         having an output for connecting the drive wheels of the rail vehicle;   having a drive connection between the input and the output which forms a transmission ratio between 5 and 10.       

     The invention is characterised in that
         the transmission ratio is formed by two transmission stages connected between one another in the drive connection, from which the first transmission stage has a transmission ratio between 1 and 2 and the second transmission stage connected downstream in the drive power flow after the first transmission stage from the input to the output has a transmission ratio of more than double the first transmission stage.

The invention concerns a transmission for the drive train of a rail vehicle, having the characteristics detailed in the preamble of the claim 1. The invention is particularly suitable for rail vehicles in regional rail traffic with maximum operating speeds of 80 to 110 km/h, and here especially in underground regional rail traffic (metro).

Single-stage spur gear transmissions are normally used for transmitting the drive power from the drive motor to the drive wheels. Due to different maximum operating speeds, which generally range between 80 km/h and 110 km/h, and due to different motor concepts, the transmission ratios previously vary in most cases between 6.3 and 7.7. This leads to the necessity that according to the transmission ratio desired by the operator, which is selected according to the maximum operating speed provided, of choosing a transmission among a plurality of stocked up or offered transmissions of different sizes and of integrating it into the rail vehicle. The manufacturers of such rail vehicle transmissions hence offer as a rule different transmissions of different sizes, with which the use of identical parts for the different transmission sizes is extremely limited. This increases the costs of manufacture and provisioning for new transmissions as well as for spare parts. The available transmission ratios are moreover limited by the prescribed ground clearance of the rail vehicle, which changes according to the diameter of the toothed gears utilised.

The object of the present invention is then to offer a transmission for the drive train of a rail vehicle, which covers the whole traditional transmission range and advantageously an even greater transmission range and enables to alter the concrete transmission ratio of the individual transmission only through minimum modifications in construction.

The object of the invention is satisfied with a transmission exhibiting the features of claim 1. Advantageous and particularly appropriate embodiments of the invention are disclosed in the dependent claims, among other things a drive train for a rail vehicle having a transmission according to the invention.

The transmission according to the invention, in particular a rail vehicle transmission, has an input for connecting a drive motor of the rail vehicle as well as an output for connecting the drive wheels of the rail vehicle. The input can be connected by way of example directly or by means of a coupling, in particular elastically coupling, immediately to the drive motor. Additional drive elements are interposed in accordance with an alternative form of embodiment.

An electric motor can be considered as an drive motor in particular. However, other motors are also possible, for instance an internal combustion engine, in particular a diesel engine, or a diesel electric input.

The output can advantageously consist of a transmission output shaft, which carries at least one input wheel or two input wheels. It is of course also possible to provide additional transmission members between the output and the input wheels or another number of input wheels arranged on the output shaft.

According to the invention, the drive connection of the transmission between the input and the output has a transmission ratio between 5 and 10, both limits included. Particularly advantageously, the transmission ratio lies in a region greater than 5 and smaller than 10, for instance of 6 to 8 (with included limits) or between 6 and 8 (without limits).

According to the invention the transmission ratio is now formed of two transmission stages connected between one another in the drive connection between the input and the output of the transmission, from which the first transmission stage has a transmission ratio between 1 and 2 and the second, transmission stage connected downstream in the drive power flow after the first transmission stage from the input to the output has a transmission ratio of more than double the first transmission stage.

Particularly advantageously, the transmission ratio of the first transmission stage is smaller than 2, in particular it is equal to 1.4 to 1.7.

the second transmission stage can advantageously have a transmission ratio of 6 to 8, in particular of 4 to 5 or particularly advantageously of 4.3 to 4.7.

According to a preferred embodiment of the invention, both transmission stages consist respectively of a pair of toothed gears, in particular pair of spur wheels. The pair of spur wheels can for instance have helically cut spur gears.

In a particular compact embodiment it is provided, that the drive connection between the input and the output of the transmission is formed exclusively by both pairs of toothed gears and those shafts and bearings associated to them. For instance, the input can consist of an input shaft of the transmission, which carries an input tooth gear of the first transmission stage, the output may consist of an output shaft, which carries an output toothed gear of the second transmission stage, and moreover a single intermediate shaft may be provided, which carries two intermediate toothed gears, among which the first meshes with the input tooth gear and the second meshes with the output toothed gear.

When mounted, in operation of the transmission, the output shaft can advantageously be positioned with its rotary axis above the intermediate shaft, in particular above the rotary axis of the intermediate shaft. The input shaft is advantageously positioned with its rotary axis also above the intermediate shaft, in particular above the rotary axis of the intermediate shaft and in particular above the rotary axis of the output shaft. It goes without saying that another positioning is possible below the rotary axis of the output shaft or below the rotary axis of the intermediate shaft.

In a particularly advantageous embodiment, the first intermediate wheel meshing with the input toothed gear on the intermediate shaft and the output toothed gear on the output shaft plunge at the same depth into a common oil sump, which for instance is provided below the toothed gears in a common housing enclosing both transmission stages. By identical depth does not necessarily mean plunging to the exactly identical depth, but rather that substantially the same immersion depth can be sufficient. By way of example, the immersion depths may differentiate by less than 15 or 10 mm.

A drive train realised according to the invention, in particular a rail vehicle drive train, comprises a drive motor for driving the rail vehicle as well as input wheels driven by the drive motor. A transmission of the type previously described is provided moreover, which is arranged in the drive power flow between the drive motor and the input wheels.

The drive train respectively the rail vehicle has a bogie in which the drive wheels are mounted.

The transmission is advantageously mounted on an output shaft forming the output and carrying the drive wheels and is supported by means of a torque support on the bogie against torsion. The torque support can be designed as a separate component, for instance as a lever, which is connected on the one hand on the transmission, in particular on a housing of the same, and on the other hand on the bogie. At least one of both ports is advantageously formed via an elastic element, to dampen oscillations. Alternately or additionally, the torque support can include an elastic element for dampening oscillations in the torque support.

According to an alternative form of embodiment, the torque support is designed integrally with the bogie or with the transmission, in particular the transmission housing. As a matter of principle, a single-piece design of all three components can also be considered.

According to an embodiment, the drive motor is also mounted in the bogie and is advantageously connected to the drive unit of the transmission via an elastic coupling which in particular allows for elastic movements in axial direction and radial direction.

Thanks to the invention, the whole necessary transmission range of a rail vehicle transmission can be covered von 80 to 110 km/h in particular at maximum operating speeds, or even rates moreover up to for instance 120 or 130 respectively 140 km/h. To change the overall transmission ratio, only minor modifications are required on the first transmission stage. The toothed gear on the input shaft of the transmission as well as the toothed gear of the intermediate shaft toothed meshing with the same can be adapted. Due to the unusually large transmission ratio selected of the second transmission stage, the necessary variation to the first transmission stage drops very little. the second transmission stage can remain unchanged.

The modifications necessary to the transmission to change the overall transmission ratio are so minimal that the maximum operating sped can only modified by adapting the first transmission stage in an existing transmission, for instance cost efficiently during a general overhaul of the rail vehicle. The possibility of considerably increasing the number of identical parts of different transmissions enables to reduce the provisioning of spare parts, to uniformise the assembly tools and to match the operating and maintenance processes of different transmissions.

The invention will now be described by way of example using an embodiment.

The figures are as follows:

FIG. 1 shows a lateral view of a transmission realised according to the invention;

FIG. 2 shows a sectional view with a cutting path through the rotary axis of the different shafts of the form of embodiment according to FIG. 1.

FIG. 1 represents an input wheel 1 of a track vehicle. The input wheel 1 is carried by output shaft 2 of a transmission. The transmission 3 properly speaking, including a transmission housing 4, is mounted on the output shaft 2 and supported against torsion by means of a torque support 5 on the bogie 6 (here, only a small part is represented.

The drive power of a drive motor (non represented in FIG. 1) is introduced via the input shaft 7 of the transmission 3 into the transmission 3. The drive power is transmitted from the input shaft 7 to the output shaft 2 via an intermediate shaft 8 by means of two pairs of toothed gears, which are subsequently described more in detail using FIG. 2.

An oil sump 9 is formed in the transmission housing 4 in the lower section, by means of which the transmission is lubricated and into which at least the output toothed gear 16 on the output shaft 2 and the toothed gear meshing with the same on the intermediate shaft 8 as well as advantageously also the toothed gear 14 of the intermediate shaft 8, which meshes with the toothed gear 13 on the input shaft 7, are immersed.

FIG. 2 clearly shows again the transmission 3 with the transmission housing 4, in which the output shaft 2, the input shaft 7 and the intermediate shaft 8 are mounted, in this instance respectively via two pairs of roller bearings respectively. The drive motor 9 is moreover represented, which for instance can be designed as an electric motor. However, other engine types, in particular a diesel engine, can also be considered. The drive motor 9 drives the input shaft 7 via an elastic coupling 10.

A first transmission stage 11 is formed by a input toothed gear 13 carried by the input shaft 7 and the first intermediate toothed gear 14 carried by the intermediate shaft 8. Both toothed gears 13, 14 are designed as spur gears, in particular as helically cut spur gears.

The second transmission stage 12 is formed by the second intermediate toothed gear 15 carried by the intermediate shaft 8 as well as the output toothed gear 16 carried by the output shaft 2.

According to the invention, the transmission ratio of the second transmission stage 12 is greater than double the first transmission stage 11, which extensively enables to vary the whole transmission ration consisting of both transmission stages, by minimal modifications of the first transmission stage 11. 

1-10. (canceled)
 11. A transmission for the drive train of a rail vehicle, comprising: an input for connecting a drive motor of the rail vehicle; an output for connecting the drive wheels of the rail vehicle; a drive connection between the input and the output which forms a transmission ratio between 5 and 10; wherein the transmission ratio is formed by two transmission stages connected between one another in the drive connection, from which the first transmission stage has a transmission ratio between 1 and 2 and the second transmission stage connected downstream in the drive power flow after the first transmission stage from the input to the output has a transmission ratio of more than double the first transmission stage.
 12. The transmission according to claim 11, wherein the drive connection between the input and the output of the transmission forms a transmission ratio between 6 and
 8. 13. The transmission according to claim 11, wherein the second transmission stage has a transmission ratio between 4 and 5, in particular between 4.3 and 4.7.
 14. The transmission according to claim 12, wherein the second transmission stage has a transmission ratio between 4 and 5, in particular between 4.3 and 4.7.
 15. The transmission according to claim 11, wherein both transmission stages are formed by respectively a pair of toothed gears, in particular a pair of spur wheels.
 16. The transmission according to claim 12, wherein both transmission stages are formed by respectively a pair of toothed gears, in particular a pair of spur wheels.
 17. The transmission according to claim 13, wherein both transmission stages are formed by respectively a pair of toothed gears, in particular a pair of spur wheels.
 18. The transmission according to claim 14, wherein both transmission stages are formed by respectively a pair of toothed gears, in particular a pair of spur wheels.
 19. The transmission according to claim 15, wherein the drive connection between the input and the output is formed exclusively by both pairs of toothed gears by shafts and bearings associated to them.
 20. The transmission according to claim 16, wherein the drive connection between the input and the output is formed exclusively by both pairs of toothed gears by shafts and bearings associated to them.
 21. The transmission according to claim 17, wherein the drive connection between the input and the output is formed exclusively by both pairs of toothed gears by shafts and bearings associated to them.
 22. The transmission according to claim 18, wherein the drive connection between the input and the output is formed exclusively by both pairs of toothed gears by shafts and bearings associated to them.
 23. The transmission according to claim 19, wherein the input is formed of an input shaft, which carries an input toothed gear of the first transmission stage, the output is formed of an output shaft, which carries an output toothed gear of the second transmission stage, and moreover an intermediate shaft is provided, which carries two intermediate toothed gears, among which the first meshes with the input toothed gear and the second meshes with the output toothed gear.
 24. The transmission according to claim 20, wherein the input is formed of an input shaft, which carries an input toothed gear of the first transmission stage, the output is formed of an output shaft, which carries an output toothed gear of the second transmission stage, and moreover an intermediate shaft is provided, which carries two intermediate toothed gears, among which the first meshes with the input toothed gear and the second meshes with the output toothed gear.
 25. The transmission according to claim 21, wherein the input is formed of an input shaft, which carries an input toothed gear of the first transmission stage, the output is formed of an output shaft, which carries an output toothed gear of the second transmission stage, and moreover an intermediate shaft is provided, which carries two intermediate toothed gears, among which the first meshes with the input toothed gear and the second meshes with the output toothed gear.
 26. The transmission according to claim 23, wherein the output shaft is positioned in built-in operating condition with its rotary axis above the rotary axis of the intermediate shaft, and the first intermediate gear wheel meshing with the input toothed gear and the output toothed gear dip in particular essentially to the same depth into a common oil sump.
 27. A drive train for a rail vehicle, comprising: a drive motor for driving the rail vehicle; drive wheels driven by the drive motor; a transmission according to claim 11, in the drive power flow between the drive motor and the drive wheels; a bogie, in which the drive wheels are mounted; wherein the transmission is mounted on an output shaft forming the output and carrying the drive wheels and rests on the bogie by means of a torque support.
 28. The drive train according to claim 27, wherein the drive motor is mounted in the bogie, and is connected via an elastic coupling which permits elastic movements in particular in axial direction and radial direction, to the input of the transmission.
 29. The drive train according to claim 27, wherein the torque support is connected by means of at least one elastic element to the bogie and/or transmission or has such an element for transmitting the supporting force or the supporting torque.
 30. The drive train according to claim 28, wherein the torque support is connected by means of at least one elastic element to the bogie and/or transmission or has such an element for transmitting the supporting force or the supporting torque. 